Question

Evaluate the following algebraic expressions such that x = 3, y = -4, and z = 5.A. (x + y)2 – (x – y)2B. 2(2x + 3y – 4z)2 – xyz

Answer 1

Given

The value of x is 3 , y is -4 and z is 5.

Step-by-step explanation

a. To find the value of the expression

`(x+y)^2-(x-y)^2`

Substitute the values of x and y

`\begin{gathered} (3+(-4))^2-(3-(-4))^2=1-49 \\ 1-49=-48 \end{gathered}`

The answer is -48.

b. To find the value of the expression

`2\left(2x+3y-4z\right)^2-xyz`

Substitute the values of x , y and z.

`\begin{gathered} 2(2*3+3(-4)-4(5))^2-3(-4)(5) \\ 2(6-12-20)^2+60 \\ 2(676)+60=1412 \end{gathered}`

The answer is 1412.